Benkongerike is a dungeon in Skyrim: Dragonborn
Head on down the slope at the entrance. Turn to the South at the bottom of the slope. You will find a small Riekling camp. There are a few Rieklings. In the back portion you will encounter a Bristleback as you make your way to the South to continue onward.
Going to the South, you will come across a few containers that you can open. Follow the path to the West to find another Riekling Camp. More Riekling Warriors and Scouts can be found in this section. Clear them out as you make your way to the West.
After the camp is a tunnel with a few odd barrels. A couple of those barrels have Rieklings inside them. Be careful traveling down the tunnel. Follow the tunnel as it turns to the North in this section.
The path slopes down just a short distance into the tunnel. Be careful because there are tripwires found in this tunnel. Either interact with the tripwire to activate them or just jump over them to avoid the trap. The trap will have a spiked wall swing in either from the left or right depending on which trip wire it is.
Farther to the North you will find another tripwire in your way. This looses a spike wall from the ceiling that swings down toward you. Head on down that passage as it turns to the East.
This leads you into a large room with a number of plateaus linked by bridges. Each of them, with the bridges, you will find more Rieklings. Make your way to the North then East across this portion of the room. Falling will force you to restart the bridge portion.
Getting to the far Eastern side you will find a doorway leading deeper into the dungeon. Follow the hallway the short distance into the next room.
In this room you have reached, you will find more Rieklings scattered throughout the room hidden in barrels. Turn to the North in this final room and you will find the passage into the great hall within. Continue to the North and take the stairs there upwards.
At the top of the stairs, head to the North. There will be an Iron Door on the left (Expert lock). If you can get into the room you will find a large chest with loot inside it. To the left you will find the Benkongerike Key that will allow you to open any remaining doors within these ruins. To the right of the chest you will find another pedestal with the book Dragon Language Myth no More.
Exit this gate and turn to the East. Head across from the door you opened and go down the hallway there.
Following this path will bring you into another large room. Once again, you will be dealing with a number of Rieklings. There will be a variety of them around on the lower floor.
Along the Southwestern side you will find some markers and rotating pillars. Go around the room and spin the pillars to match the icon above them. Going from the far right to left: Snake, Whale, Whale (no icon), Hawk.
Once all the icons are lined up properly, head to the pull handle in front of the gate. The gate will open. Head inside. You will find a Word Wall. It has "Gaar" for the Cyclone shout. In front of the wall is also a Boss Chest you can loot.
With all that collected, turn around and look to the East. You will find a path that leads into the wall. Follow this all the way to its end to find Black Book Untold Legends. Open the book to begin its quest and gain the power within.